hmm, why selling Cognitive?
Same reason I was selling YABMC. It took a while to realize, but by holding mining securities and taking BTC-denominated deposits, I'm effectively shorting BTC, which is not a bet I'd like to take at this time. Beyond that, I don't place extra value on holding equity vs. debt, so Cognitive is overpriced by my own valuation (though underpriced compared to comparable equities). Mining hardware will depreciate at roughly the same rate as a MH/s (particularly FPGAs/ASICs, while GPUs are probably immune to difficulty-related depreciation since mining is a pretty obscure use for them - but GPUs will depreciate for other reasons).
Anyhoo, YABMC sale's off the table and I'm locking this thread. Cheers!